Granular herbicide

ABSTRACT

This invention provides a granular herbicide for direct foliage application to undesirable plants, which contains a water soluble, non-selective foliage-application type herbicidally active compound as the active ingredient, having an average granule size within a range of 0.21-1 mm and an elution ratio of said active ingredient of at least 20% when 20 mg of the granular herbicide is treated with a circular filter paper sheet of 55 mm in diameter which is impregnated with 50 μl of water.

TECHNICAL FIELD

[0001] This invention relates to a granular herbicide for foliageapplication directly onto undesirable plants, which contains a watersoluble, non-selective foliage application type herbicidally activecompound such as glyphosate; and to a process for killing or controllingundesirable plants using said herbicide.

BACKGROUND ART

[0002] Non-selective foliage application type herbicidally activecompounds such as glyphosate kill or control many species of weedsnon-selectively, and hence have been used in non-agricultural land suchas railways, created land, parking lots, parks and house circumferences.Furthermore, because said herbicidally active compounds falling on soilsurface lose their herbicidal activity against plants after they areadsorbed in the soil and exhibit no phytotoxicity for useful plants,they are widely used also in agricultural land such as orchard,vegetable gardens and paddy fields before ploughing. Conventionally, foruniformly applying such a non-selective foliage application typeherbicidal compound as glyphosate to allow exhibition of its maximumeffect, generally such a non-selective foliage application typeherbicidally active compound is formulated into such preparation formsas liquid, water soluble granule, flowable, wettable powder and thelike, and a method of diluting said preparation forms with water isadopted.

[0003] These preparations, however, are difficult for use where waterfacilities are bad because they are used as diluted with water.Moreover, for spraying these preparations, suitable devices such as asprayer is indispensable. Besides such problems, their application witha sprayer scatters fine spray particles which are apt to be drifted withwind. Therefore, their spray in the vicinities of useful plants or tothe areas close to plant bases is liable to cause phytotoxicity, and isnormally avoided.

[0004] On the other hand, recently water soluble granule or waterdispersible granule preparations are developed in consideration of theproblems incidental to disposal of containers and toxicity of solventsused in emulsifiable concentrate, and also for such reasons as theirbetter flowability and easier measurement compared with water solublepowder or wettable powder preparations. Furthermore, they do not causedust scattering in the occasions of preparing spraying liquidstherefrom, exhibiting improved safety for the workers. As water solublegranule or water dispersible granule preparations containing glyphosateas herbicidally active ingredient, for example, water dispersiblegranule preparations comprising glyphosate and polyglycolether nonionicsurfactant having a wax viscosity [JP Hei 6 (1994)-256121A] or watersoluble granule preparations comprising glyphosate, a surfactant andpolyalkylene glycol as an extrusion granulating assistant [JP Hei 11(1999)-255609A] have been proposed. These water soluble granule or waterdispersible granule preparations, however, are invariably to be dilutedwith water before application, like liquid, emulsifiable concentrate orflowable preparations and the problems as above-described still remainunsolved.

DISCLOSURE OF THE INVENTION

[0005] We have engaged in concentrative studies with the view to solveabove problems to discover: surprisingly, when water soluble,non-selective foliage application type herbicidally active compoundssuch as glyphosate are formulated into small size granular preparationswhich contain said herbicidally active compounds in a state allowingquick elution thereof, and directly applied to weeds as they are, thegranular preparations are effectively deposited and retained on foliageof the weeds and readily eluted with minor amounts of water such as thenight dew or morning dew to accomplish fully satisfactory herbicidaleffect, whereby solving all of the problems of water facilities,spraying equipment, drifting with wind, etc. at once. The presentinvention is whereupon completed.

[0006] Thus, the present invention provides a granular herbicide fordirect foliage application to undesirable plants, which contains a watersoluble, non-selective foliage application type herbicidally activecompound as the active ingredient, characterized by having an averagegranule size within a range of 0.21-1 mm and an elution ratio of saidactive ingredient of at least 20% when 20 mg of the granular herbicideis treated with a circular filter paper sheet of 55 mm in diameter whichis impregnated with 50 μl of water.

[0007] The present invention also provides a method of killing orcontrolling undesirable plants, characterized by directly applying saidgranular herbicide onto foliage of undesirable plants.

[0008] Hereinafter the granular herbicide and the method of its use ofthe present invention are explained in further detail.

EMBODIMENTS OF THE INVENTION

[0009] The herbicidally active compound which is used as the activeingredient in the granular herbicide of the present invention is watersoluble and is of a type to be absorbed through plant foliage to kill orcontrol the plants non-selectively. The compound suitably has solubilityin water of at least 10 g/liter at 20° C. Said herbicidally activecompound desirably is such that its herbicidal activity is substantiallylost when it drops on soil surface and is adsorbed into the soil. Asspecific examples of this type of herbicidal compound (which mayhereafter be referred to as “herbicidal ingredient of the presentinvention”), glyphosate or salts thereof (e.g., sodium salts, ammoniumsalts, isopropylamine salts, trimesium salts and the like), bialaphos,glyfosinate, diquat, paraquate and the like can be named, the herbicidalingredient of the present invention not being limited to theabove-named. Of these, particularly glyphosate and salts thereof arepreferred.

[0010] According to the invention, these granular herbicides areformulated into such a granular preparation form having an averagegranule size within a range of 0.21-1 mm, preferably 0.3-0.8 mm, interalia, 0.5-0.8 mm and an elution ratio of the herbicidal ingredient ofthe present invention from the preparation as measured by the followingmethod of at least 20%, preferably at least 40%, inter alia, at least50%.

Method for Measuring Elution Ratio of Herbicidal Ingredient of thePresent Invention

[0011] Fifty (50) ml of distilled water is weighed with a micropipetteand dropped on the central area of a circular filter paper sheet of 55mm in diameter (ADVANTEC Co., No.5C). At the time the water has diffusedand infiltrated over the entiety of the filter paper (in about 2minutes), accurately weighed 20 mg of a sample preparation is dispersedon the filter paper, taking care that the granules shall not overlapwith each other.

[0012] The filter paper on which the sample preparation is dispersed isimmediately put in a desiccator containing water at its bottom portionand left there for an hour. The filter paper is withdrawn from thedesiccator, mildly patted to remove the preparation remaining thereonand thereafter extracted with 10 ml of distilled water. The herbicidalingredient of the present invention contained in the extracted solutionis determined by high performance liquid chromatography (HPLC analysis),and from the determined value the eluted amount a mg of the herbicidalingredient per mg of the sample preparation is decided.

[0013] Separately, accurately weighed 20 mg of a sample preparation isdispersed in 10 ml of distilled water to cause complete elution of theherbicidal ingredient of the present invention in the sample preparationinto the water which then is centrifuged. The supernatant is given anHPLC analysis to determine the herbicidal ingredient contained in thesupernatant, and from the determined value the amount b mg of theherbicidal ingredient contained per mg of the sample preparation isdecided.

[0014] The elution ratio(%) of the herbicidal ingredient of the presentinvention from the sample preparation is calculated by a formula,

a/b×100.

[0015] Granular herbicides of the present invention can be adjusted oftheir average granule size to fall within a range of 1.0 mm-0.21 mm, bymeans of combined selection of a screen diameter of the granulatingmachine used (between 1.0 mm-0.2 mm) and mesh size of the sieve used(between 1.0 mm-0.21 mm).

[0016] Granular herbicides of the present invention having the specifiedaverage granule size and the specified elution ratio of herbicidalingredient of the present invention can be formulated following acceptedformulation methods of water dispersible granule preparations, forexample, by granulating one or more of the herbicidal ingredients of thepresent invention together with surfactants, binders and carriers, andfurther with polyhydric alcohols where necessary.

[0017] Surfactants useful for formulating granular herbicides of thepresent invention are subject to no specific limitation, and forexample, any of anionic surfactants such as alkylbenzenesulfonate,alkylnaphthalenesulfonate, naphthalenesulfonate-formaline condensate,dialkylsulfosuccinate, lignin sulfonate, α-olefin sulfonate, alkanesulfonate, polystyrene sulfonate, alkyl ether sulfate salt,polyoxyethylene alkyl ether sulfate salt, polyoxyethylene alkylphenylether sulfate salt, polyoxyethylene polystyrylphenyl ether sulfate-salt,polyoxyethylene alkyl ether phosphate salt, polyoxyethylene alkyl phenylether phosphate salt, polyoxyethylene polystyryl phenyl ether phosphatesalt, fatty acid salt, isobutylene-maleic acid copolymer salt,styrene-maleic acid copolymer salt, polyacrylic acid salt and the like;nonionic surfactants such as silicone-type surfactants, polyoxyethylenealkyl ether, polyoxyethylene alkyl phenyl ether,polyoxyethylenestyrylphenyl ether, polyoxyethylenestyrylphenyl etherpolymer, polyoxyethylenesorbitan alkyl ester, polyoxyethylenepolyoxypropylene block polymer, polyoxyethylene alkyl ester,polyoxyethylene alkylamine and the like; and cationic surfactants suchas alkylamine salt, tetraalkylammonium salt, trialkylbenzylammonium saltand the like can be named. Furthermore, ampholytic surfactants or thelike may be used, where necessary. These surfactants can be used eithersingly or in combination of two or more. The use rate of thesesurfactants is not critical, and from such considerations as the effectand economy, generally their use within a range of 0.1-30% by weight, inparticular, 2-10% by weight, to the total amount of the preparation isdesirable.

[0018] Binders useful for formulating the granular herbicides of thepresent invention is again subject to no particular limitation. Forexample, starch, hydrogenated starch hydrolysate, dextrin, cellulose,methyl cellulose, ethyl cellulose, carboxymethyl cellulose, hydroxyethylcellulose, hydroxypropyl cellulose, carboxymethyl starch, pullulan,sodium alginate, ammonium alginate, alginic acid propylene glycol ester,guar gum, locust bean gum, gum arabi, xanthane gum, gelatine, casein,polyvinyl alcohol, polyethylene oxide, polyethylene glycol,ethylene/propylene block polymer, sodium polyacrylate,polyvinylpyrrolidone and the like can be named. These binders can beused either singly or in combination of two or more. While the use rateof these binders is subject to no specific limitation, generally theiruse within a range of 0.1-40% by weight, in particular, 2-10% by weight,to the total amount of the preparation is desirable from the standpointsof effect and economy.

[0019] Carriers useful for formulating the granular herbicides of thepresent invention may be either inorganic or organic carriers, and aresubject to no specific limitation, examples of inorganic carriersincluding clay, bentonite, talc, calcium carbonate, sodium carbonate,zeeklite, sericite, acid clay, quartzite, diatomaceous silica, pumice,zeolite, vermiculite, potassium chloride, urea, white carbon, ammoniumsulfate, sodium sulfate, perlite, magnesium sulfate, attapulgite and thelike; and examples of organic carriers including glucose, maltose,sucrose, lactose and the like. These inorganic or organic carriers canbe used singly, or two or more of these inorganic carriers and/ororganic carriers may be concurrently used.

[0020] Furthermore, polyhydric alcohols which can be optionally used forformulating the granular herbicides of the present invention are subjectto no specific limitation, examples of which including glycerine,ethylene glycol, diethylene glycol, propylene glycol, hexylene glycol,polyethylene glycol, polypropylene glycol, xylitol, maltitol, butyleneglycol, polyoxyethylene methyl glycoside, mannitol, sorbitol and thelike. The use rate of these polyhydric alcohols is not critical, butgenerally their use within a range of 0.1-40% by weight, in particular,2-20% by weight, to the total amount of the preparation is desirablefrom the standpoints of effect and economy.

[0021] Formulation method of granular herbicides of the presentinvention is subject to no specific limitation so long as therequirements for the average granule size and the elution ratio ofherbicidal ingredient of the present invention are satisfied. Normally,however, the formulation can be carried out, for example, by thefollowing methods: the herbicidal ingredient of the present invention ismixed with surfactants, binders and carriers, and further optionallywith polyhydric alcohols; then 1) the mixture is kneaded with additionof water, granulated with an extrusion granulating machine, adjusted ofthe granule size, dried and sieved; 2) the mixture is granulated with atumbling granulating machine under addition of water, adjusted of thegranule size, dried and sieved; 3) the mixture is dispersed in water,granulated with a spray granulating machine, adjusted of the granulesize, dried and sieved; or 4) onto a flowing mixture of surfactants andcarriers, the herbicidally active ingredient and a binder solution aresprayed and granulated with a fluidized bed granulating machine,adjusted of the granule size, dried and sieved. The sieving can becarried out using sieves with mesh sizes between 1.0 mm and 0.21 mm incombination.

[0022] The adjustment of the elution ratio of herbicidal ingredient ofthe present invention from so formulated preparation can be conductedwith ease, by adjusting the use rate of the surfactants and/or binders.

[0023] Content of the herbicidal ingredient of the present invention inso formulated granular herbicide of the present invention is notstrictly limited, and may be varied according to the kind of theherbicidal ingredient used. Generally, however, the content preferablylies within a range of 0.01-90% by weight, in particular, 0.1-60% byweight, inter alia, 2-25% by weight, to the total amount of thepreparation.

[0024] The granular herbicides provided by the present invention areapplicable directly to foliage of undesirable plants, retaining theirgranular preparation form, without being diluted with water likeconventional herbicides. The application can be done by scattering thegranular herbicidal preparation as it is, either by hand or from itscontainer directly over plant foliage, or at a place like a large field,it is also permissible to use an application tool like a granuleapplicator for direct application of the preparation onto plant foliage.

[0025] The direct application causes the granular herbicide of thepresent invention to fall and be deposited on foliage of undesirableplants, and from the herbicide its herbicidal ingredient is readilyeluted with such miner amount of moisture like night dew or morning dew(in certain cases the herbicide granules are readily collapsed anddispersed to allow elution of the herbicidal ingredient). The elutedherbicidal ingredient is absorbed by the plant foliage, to exhibitexcellent herbicidal effect as well as applying conventional wettablepowder or liquid preparations after dilution with water.

[0026] The granular herbicidal preparations of the present invention canbe applied, for example, to industrial parks, shoulders or slopes ofrailroad or driveway, orchards (e.g., vineyard, orange orchard and thelike), tea gardens, forest lands, playgrounds, well-wooded gardens andthe like, to control undesirable plant species present in such areas.The application rate of the granular herbicidal preparation of thepresent invention in such occasions is variable over a broad rangedepending on the kind of the herbicidal ingredient, the species ofplants to kill or control, and percentage of vegetational cover.Whereas, generally suitable application rate ranges 50 g/a-2000 g/a, inparticular, 150 g/a-300 g/a.

[0027] Application of the granular herbicide of the present invention ispreferably carried out on a windless or faintly windy day. It is alsomore effective to carry it out in the evening when night dew or morningdew are apt to fall.

EXAMPLES

[0028] Hereinafter the invention is explained more specifically,referring to working examples, it being understood that the invention isnot limited to these examples.

Example 1

[0029] Glyphosate isopropylamine salt 21 wt %,polyoxyethylenestyryl-phenyl ether 10 wt %, starch 10 wt % anddiatomaceous silica 59 wt % were measured into a mixing vessel and mixedfor 5 minutes with a universal mixer. Thirty (30) wt % of water per 100wt % of this mixture was added and together kneaded for further 5minutes. The kneaded product was granulated with a basket typegranulating machine equipped with a 0.8 mm mesh size screen (HataIronworks Co.). The size-adjusted granules obtained were dried and thensifted (1.0-0.21 mm) to provide a granular herbicidal preparation(Example-1).

Example 2

[0030] Glyphosate isopropylamine salt 21 wt %, dialkylsulfosuccinate 10wt %, sodium polyacrylate 2 wt % and diatomaceous silica 67 wt % weremeasured into a mixing vessel and mixed for 5 minutes with a universalmixer. Thirty (30) wt % of water per 100 wt % of this mixture was addedand together kneaded for further 5 minutes. The kneaded product wasgranulated with a basket type granulating machine equipped with a 0.8 mmmesh size screen (Hata Ironworks Co.). So obtained size-adjustedgranules were dried and sifted (1.0-0.21 mm) to provide a granularherbicidal preparation (Example-2).

Example 3

[0031] Glyphosate isopropylamine salt 21 wt %, dialkylsulfosuccinate 10wt %, sodium polyacrylate 2 wt % and diatomaceous silica 67 wt % weremeasured into a mixing vessel and mixed for 5 minutes with a universalmixer. Thirty (30) wt % of water per 100 wt % of this mixture was addedand together kneaded for further 5 minutes. The kneaded product wasgranulated with a basket type granulating machine equipped with a 0.5 mmmesh size screen (Hata Ironworks Co.). So obtained size-adjustedgranules were dried and sifted (1.0-0.21 mm) to provide a granularherbicidal preparation (Example-3).

Example 4

[0032] Glyphosate isopropylamine salt 21 wt %, dialkylsulfosuccinate 6wt %, polyoxyethylene alkyl ether 4 wt %, sodium polyacrylate 2 wt %,diatomaceous silica 57 wt % and bentonite 10 wt % were measured into amixing vessel and mixed for 5 minutes with a universal mixer.Twenty-four (24) wt % of water per 100 wt % of this mixture was addedand together kneaded for further 5 minutes. The kneaded product wasgranulated with a basket type granulating machine equipped with a 0.8 mmmesh size screen (Hata Ironworks Co.). So obtained size-adjustedgranules were dried and sifted (1.0-0.21 mm) to provide a granularherbicidal preparation (Example-4).

Example 5

[0033] Glyphosate isopropylamine salt 7 wt %, dialkylsulfosuccinate 6 wt%, polyoxyethylene alkyl ether 4 wt %, sodium polyacrylate 2 wt %,diatomaceous silica 71 wt % and bentonite 10 wt % were measured into amixing vessel and mixed for 5 minutes with a universal mixer. Thirty(30) wt % of water per 100 wt % of this mixture was added and togetherkneaded for further 5 minutes. The kneaded product was granulated with abasket type granulating machine equipped with a 0.8 mm mesh size screen(Hata Ironworks Co.). So obtained size-adjusted granules were dried andsifted (1.0-0.21 mm) to provide a granular herbicidal preparation(Example-5).

Example 6

[0034] Glyfosinate 10 wt %, alkylamine salt 10 wt %, carboxymethylcellulose 2 wt %, diatomaceous silica 68 wt % and bentonite 10 wt % weremeasured into a mixing vessel and mixed for 5 minutes with a universalmixer. Twenty-four (24) wt % of water per 100 wt % of this mixture wasadded and together kneaded for further 5 minutes. The kneaded productwas granulated with a basket type granulating machine equipped with a0.8 mm mesh size screen (Hata Ironworks Co.). So obtained size-adjustedgranules were dried and sifted (1.0-0.21 mm) to provide a granularherbicidal preparation (Example-6).

Example 7

[0035] Bialaphos 10 wt %, dialkylsulfosuccinate 10 wt %, sodiumpolyacrylate 2 wt %, diatomaceous silica 68 wt % and bentonite 10 wt %were measured into a mixing vessel and mixed for 5 minutes with auniversal mixer. Twenty-four (24) wt % of water per 100 wt % of thismixture was added and together kneaded for further 5 minutes. Thekneaded product was granulated with a basket type granulating machineequipped with a 0.8 mm mesh size screen (Hata Ironworks Co.). Soobtained size-adjusted granules were dried and sifted (1.0-0.21 mm) toprovide a granular herbicidal preparation (Example-7).

Example 8

[0036] Glyphosate isopropylamine salt 21 wt %, dialkylsulfosuccinate 10wt %, glycerine 15 wt %, sodium polyacrylate 2 wt % and diatomaceoussilica 52 wt % were measured into a mixing vessel and mixed for 5minutes with a universal mixer. Twenty (20) wt % of water per 100 wt %of this mixture was added and together kneaded for further 5 minutes.The kneaded product was granulated with a basket type granulatingmachine equipped with a 0.8 mm mesh size screen (Hata Ironworks Co.). Soobtained size-adjusted granules were dried and sifted (1.0-0.3 mm) toprovide a granular herbicidal preparation (Example-8).

Example 9

[0037] Glyphosate isopropylamine salt 7 wt %, dialkylsulfosuccinate 6 wt%, polyoxyethylene alkyl ether 4 wt %, sodium polyacrylate 2 wt %,glycerine 15 wt %, diatomaceous silica 56 wt % and bentonite 10 wt %were measured into a mixing vessel and mixed for 5 minutes with auniversal mixer. Twenty (20) wt % of water per 100 wt % of this mixturewas added and together kneaded for further 5 minutes. The kneadedproduct was granulated with a basket type granulating machine equippedwith a 0.8 mm mesh size screen (Hata Ironworks Co.). So obtainedsize-adjusted granules were dried and sifted (1.0-0.3 mm) to provide agranular herbicidal preparation (Example-9).

Comparative Example 1

[0038] Glyphosate isopropylamine salt 25 wt %, sodium ligninsulfonate 5wt %, sodium dodecylbenzenesulfonate 0.3 wt %, white carbon 34 wt %,talc 18.7 wt % and bentonite 17 wt % were measured into a mixing vesseland mixed for 5 minutes with a universal mixer. Fifty-five (55) wt % ofwater per 100 wt % of this mixture was added and together kneaded forfurther 5 minutes. The kneaded product was granulated with a basket typegranulating machine equipped with a 0.8 mm mesh size screen (HataIronworks Co.). So obtained size-adjusted granules were dried and sifted(1.0-0.21 mm) to provide a granular herbicidal preparation (ComparativeExample-1).

Comparative Example 2

[0039] Glyphosate isopropylamine salt 25 wt %, isobutylene-maleic acidcopolymer 2 wt %, alkylbenzenesulfonate 10 wt %, carboxymethyl cellulose5 wt %, perlite 45 wt % and clay 13 wt % were measured into a mixingvessel and mixed for 5 minutes with a universal mixer. Thirty-six (36)wt % of water per 100 wt % of this mixture was added and togetherkneaded for further 5 minutes. The kneaded product was granulated with abasket type granulating machine equipped with a 0.8 mm mesh size screen(Hata Ironworks Co.). So obtained size-adjusted granules were dried andsifted (1.0-0.21 mm) to provide a granular herbicidal preparation(Comparative Example-2).

Comparative Example 3

[0040] Glyphosate isopropylamine salt 25 wt %, alkylbenzenesulfonate 10wt %, silicone-type surfactant 6 wt %, carboxymethyl cellulose 2 wt %,diatomaceous silica 40 wt % and clay 17 wt % were measured into a mixingvessel and mixed for 5 minutes with a universal mixer. The kneadedproduct was granulated with a basket type granulating machine equippedwith a 0.8 mm mesh size screen (Hata Ironworks Co.). So obtainedsize-adjusted granules were dried and sifted (1.0-0.21 mm) to provide agranular herbicidal preparation (Comparative Example-3).

Comparative Example 4

[0041] Glyphosate isopropylamine salt 21 wt %, dialkylsulfosuccinate 10wt %, sodium polyacrylate 2 wt % and diatomaceous silica 67 wt % weremeasured into a mixing vessel and mixed for 5 minutes with a universalmixer. Thirty (30) wt % of water per 100 wt % of this mixture was addedand together kneaded for further 5 minutes. The kneaded product wasgranulated with a basket type granulating machine equipped with a 1.5 mmmesh size screen (Hata Ironworks Co.). So obtained size-adjustedgranules were dried and sifted (1.68-1 mm) to provide a granularherbicidal preparation (Comparative Example-4).

Comparative Example 5

[0042] KUMIAI KUSA TOBAN™ manufactured by Kumiai Chemical Industry Co.Ltd. (a glyphosate ammonium salt water soluble granule, containing 20%of glyphosate ammonium salt) (Comparative Example-5) was used in itssold form.

Comparative Example 6

[0043] KARUNAKUSU™ manufactured by Yashima Chemical Industry Co., Ltd.(a glyphosate isopropylamine salt liquid preparation containing 41.0% ofglyphosate isopropylamine salt) (Comparative Example-6) was used in itssold form.

Comparative Example 7

[0044] BASTA (Liquid)™ manufactured by Nissan Chemical Industries, Ltd.(a glyfosinate liquid preparation containing 18.5% of glyfosinate)(Comparative Example-7) was used in its sold form.

Comparative Example 8

[0045] HERBY (Liquid)™ manufactured by Hokko Chemical Industry Co., Ltd.(a bialaphos liquid preparation containing 18% of bialaphos)(Comparative Example-8) was used in its sold form.

[0046] Ellution ratios of herbicidally active ingredients from thegranular herbicides as obtained in above Examples 1-9 and ComparativeExample 1-4; the water soluble granule preparation of ComparativeExample 5, were measured by the earlier described method. The result wasas shown in the following Table 1.

Test Example 1 (Elutability test)

[0047] TABLE 1 No. Elution ratio (%) Example 1 48 2 60 3 68 4 55 5 61 656 7 60 8 65 9 66 Comparative Example 1 0 2 9 3 14 4 58 5 6

[0048] Using the granular herbicides obtained in above Example 1-9 andComparative Examples 1-4; the water soluble granule preparation ofComparative Example 5; and the herbicidal liquid preparations ofComparative Examples 6-8, their herbicidal effect was evaluated.

Test Example 2 (Pot Test)

[0049] Pots of each 1/3000a scale were filled with upland soil and ontowhich seeds of southern crabgrass [Digitaria ciliaris (Retz.) Koeled],slender amaranthus [Amaranth us viridis L.] and common lambsquarters[Chenopodium album L.] were planted, covered up with the soil, and afterthe crabgrass grew to about 20-30 cm in height, the granular herbicidesof Examples 1-9 and Comparative Examples 1-4, the water soluble granulepreparation of Comparative Example 5 and the herbicidal liquidpreparations of Comparative Examples 6-8 were applied.

[0050] The modes of application were as follows: the granular herbicidesof Examples 1-9 and Comparative Examples 1-4 were hand-scattered as theywere, not being diluted with water; each prescribed amount of theherbicidal liquid preparations of Comparative Examples 6-8 were dilutedwith 10 liters/a of water and applied with a hand sprayer; and the watersoluble granule preparation of Comparative Example 5 was applied in twoways, i.e., either hand-scattered as it was, without being diluted, or aprescribed amount thereof was diluted with 10 liters/a of water andapplied with a hand-sprayer. Onto the sections where the granularherbicides of Examples 1-9 and Comparative Examples 1-4, and the watersoluble granule preparation of Comparative Example 5 were applied byhand, water was lightly sprinkled with a hand-spryer in advance of theherbicide application. The test was conducted in four replicates.

[0051] Four weeks after the application, herbicidal effect was evaluatedbased on the following ratings. The results were as given in thefollowing Table 2. Evaluation standard 5 kill or control ratio at least90% 4 kill or control ratio 70-90% 3 kill or control ratio 40-70% 2 killor control ratio 20-40% 1 kill or control ratio  5-20% 0 kill or controlratio 5% or less

[0052] TABLE 2 Application rate Herbicidal effect Chemical Applicationrate of active ingredient Dilution southern slender common preparation(g, ml/a) (gai/a) with water crabgrass amaranthus lambsquartersExample-1 97.6 20.5 No 5 5 5 Example-2 97.6 20.5 No 5 5 5 Example-3 97.620.5 No 5 5 5 Example-4 97.6 20.5 No 5 5 5 Example-5 292.8 20.5 No 5 5 5Example-6 92.5 9.25 No 5 5 5 Example-7 90.0 9.0 No 5 5 5 Example-8 97.620.5 No 5 5 5 Example-9 292.8 20.5 No 5 5 5 Comparative 82.0 20.5 No 0 00 Example-1 Comparative 82.0 20.5 No 0 1 0 Example-2 Comparative 82.020.5 No 1 2 1 Example-3 Comparative 97.6 20.5 No 0 0 0 Example-4Comparative 102.5 20.5 No 1 1 1 Example-5 Yes 5 5 5 Comparative 50.020.5 Yes 5 5 5 Example-6 Comparative 50.0 9.25 Yes 5 5 5 Example-7Comparative 50.0 9.0 Yes 5 5 5 Example-8

Test Example 3 (Field Test)

[0053] Mowing a simple community of southern crabgrass (percentage ofvegetational cover: 90-98%) in the orchard of a laboratory, the granularherbicides of Examples 1-9 and Comparative Examples 1-4, the watersoluble granule preparation of Comparative Example 5 and the herbicidalliquid preparations of Comparative Examples 6-8 were applied when theregrown crabgrass reached 15-20 cm in height.

[0054] The modes of application were as follows: the granular herbicidesof Examples 1-9 and Comparative Examples 1-4 were hand-scattered as theywere, not being diluted with water; each prescribed amount of theherbicidal liquid preparations of Comparative Examples 6-8 were dilutedwith 10 liters/a of water and applied with a hand sprayer; and the watersoluble granule preparation of Comparative Example 5 was applied in twoways, i.e., either hand-scattered as it was, without being diluted, or aprescribed amount thereof was diluted with 10 liters/a of water andapplied with a hand sprayer.

[0055] The test was conducted in two replicates, over the areas of 1 m²each. The applications were performed under the condition that morningdew was no more present so that moisture supply would come from themorning dew falling on the next day.

[0056] After four weeks of the application, the herbicidal effect wasevaluated based on the same rating standard as used in Test Example 2.The results were as given in the following Table 3. TABLE 3 ApplicationHerbicidal Application rate of active Dilution effect Chemical rateingredient with Southern preparation (g, ml/a) (gai/a) water crabgrassExample-1 97.6 20.5 No 5 Example-2 97.6 20.5 No 5 Example-3 97.6 20.5 No5 Example-4 97.6 20.5 No 5 Example-5 292.8 20.5 No 5 Example-6 92.5 9.25No 5 Example-7 90.0 9.0 No 5 Example-8 97.6 20.5 No 5 Example-9 292.820.5 No 5 Comparative 82.0 20.5 No 0 Example-1 Comparative 82.0 20.5 No0 Example-2 Comparative 82.0 20.5 No 1 Example-3 Comparative 97.6 20.5No 0 Example-4 Comparative 102.5 20.5 No 0 Example-5 Yes 5 Comparative50.0 20.5 Yes 5 Example-6 Comparative 50.0 9.25 Yes 5 Example-7Comparative 50.0 9.0 Yes 5 Example-8

Effect of the Invention

[0057] As clearly demonstrated by the above test results, these granularherbicides of the present invention, which are imparted with theproperty of giving an elution ratio of the herbicidally activeingredient of at least 20% when 20 mg of a tested herbicide is treatedwith a circular filter paper sheet of 55 mm in diameter which isimpregnated with 50 μl of water, exhibit the intended effect whendirectly applied onto foliage of weeds as they are, without beingdiluted with water, through the mechanism that the active ingredient inthe granular herbicides which fell and were deposited on the weedfoliage is readily eluted with water of about a quantity supplied bymorning dew or more and absorbed by the weed foliage. Furthermore, thegranular herbicides of the present invention do not require any specialapplication tool or apparatus but can be applied with hand or from theircontainers directly onto weeds, to achieve equivalent herbicidal effectto the cases of using conventional application method of diluting aliquid preparation with water and applying the same with a sprayer orthe like, while avoiding chemical injury on ambient crops caused bydrifting.

1. A granular herbicide for direct foliage application to undesirableplants, which contains a water soluble, non-selectivefoliage-application type herbicidally active compound as the activeingredient, characterized by having an average granule size within arange of 0.21-1 mm and an elution ratio of said active ingredient of atleast 20% when 20 mg of the granular herbicide is treated with acircular filter paper sheet of 55 mm in diameter which is impregnatedwith 50 μl of water.
 2. A granular herbicide according to claim 1, inwhich the water soluble, non-selective foliage-application typeherbicidally active compound is at least one compound selected from thegroup consisting of glyphosate or its salts, bialaphos, glyfosinate,diquat and paraquate.
 3. A granular herbicide according to claim 1, inwhich the water soluble, non-selective foliage-application typeherbicidally active compound is glyphosate or its salt.
 4. A granularherbicide according to claim 1, in which the herbicidally activecompound has a water solubility of at least 10g/liter at 20° C.
 5. Agranular herbicide according to claim 1, having an average granule sizewithin a range of 0.21-1 mm.
 6. A granular herbicide according to claim1, in which the elution ratio of the active ingredient is at least 40%.7. A granular herbicide according to claim 1, which is obtained byforming the herbicidally active compound into granules, withsurfactant(s), binder(s) and carrier(s), and further optionally withpolyhydric alcohol(s).
 8. A granular herbicide according to claim 1,which contains 0.01-90% by weight, preferably 1-60% by weight, of theherbicidally active compound.
 9. Method for killing or controllingundesirable plants, characterized by directly applying the granularherbicide of claim 1 to foliage of undesirable plants.
 10. Use of thegranular herbicide of claim 1 for killing or controlling undesirableplants.